Treating materials in electric furnaces.



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TREATING MATERIALS IN ELECTRIC FURNACES.

Specification of Letters Patent.

Patented Nov. 16, 1915.

Application filed April 21, 1915. Serial No. 22,783.

To all whom it may concern:

Be it known that I, EDWARD SALOMON BERGLUND, engineer, residing at Trollhilttan, Sweden, have invented certain new and useful Improvements in Treating Materials in Electric Furnaces, of which the following is a specification.

When treating a charge in an electric furnace great inconveniences often arise in view of the fact, that coverings or crusts of stiffened slag, metal or substances of the charge are formed on the furnace walls, especially in the proximity of the tap hole, at which place the furnace during the tapping operation is most subjected to cooling effects. This circumstance makes the tappingvery diflicult, no difference which method is employed for-the purpose.

The present invention has for its object to avoid these inconveniences and consists 1n adding substances in the furnace at intervals, which are easily fusible or together with the stiffened crusts form an easily :fusible or easily fiuxible slag.

The method can'be carried out in different manners. A special charge, mixed with such substances,

I may be introduced in the furnace, or such substances alone may be introduced in the furnace through special openings in the arch or in the wall of the furnace, if desired in proximity to the places, Where the tapping operation is carried out. The charge or the substances may also be introduced through the ordinary openings of introduction, but in such cases said charge or said substances must be added in large quantities, so that the hole charge in the furnace is changed,

which is very expensive and sometimes results in other inconveniences. Moreover the tapping operation takes more time, whereas it often is important for the uniform work ing of the furnace to perform the tapping of slag and metal quickly.

In order to make the invention fully understoodfone example of the substance or substances, which has proved suitable to produce the result set forth and the suitable proportions of such substances Will be mentioned. To a charge, containing zinc-ore, carbon and flux in proportions commonly used for extracting zinc in an electric furnace and Weighing 1.000 kg. is added 2-00 forth, so that the extraction operation is performed at the intervals between the tapping kg. fiuor spar, Which is intimately mixed with the charge mentioned. Or 100 to 200 kg. fluor spar alone or a mixture of' 100 kg. fluor spar, 100 kg. slag and 100 kg. lime is introduced in the electric furnace before the tapping operation isperformed throughoneor more openings in the furnace Wall in proximity to the place or places, Where the tapping operation is performed. In all cases, the tapping operation is considerably facilitated by adding the substances mentioned before thetapping is to be performed, it being understood, that such additional introduction of substances, it may be by mixing them with the ordinary charge, or by introducing them separately in the furnace. is performed temporarily as set operations With a charge of ordinary 'composition, said charge being changed by adding the said substances or introducing said substances only at times before the tapping operations.

Having now described my invention What I claim as new is:

1. The method of continuously treating material .in electric furnaces, which consists in permitting the extracting operation to take place With the ordinary charge for certain periods and at the ends of such periods and before the tapping operations-are performed introducing substances capable of forming an easily fusible slag.

2. The method of continuously treating material in electric furnaces consisting in introducing substances, forming an easily fusible slag, at intervals'du-ring the treating operation, in proximity to the places of tapping and before the tapping'operations are performed.

3. The method of continuously treating material in electric furnaces, Which consists in permitting the extracting operation to take place With the ordinary charge. for certain periods and at the ends of such periodsand before thetapping operations are performed introducing a quantity of substances capable of forming an easily fusible slag, said quantity of substances being in addition to the quantity of similar. substances contained in the ordinary charge.

4. The method of continuously treating posed of a quantity of the ordinary charge material in electric furnaces, which consists and a quantity of substances capable of in permitting the extracting operation to forming an easily fuslble slag.

I take place with the ordinary charge for cer- EDWARD SALOMON BERGLUND. 5- tain periods and at the ends of such periods Witnesses:

and before the tapping operations are per- HUGo LmnBURG,

formed introducin a mixed charge com- BENCH ONSELL. 

